@tao@social.coop @edsu i started doing something similar (just an excercise to learn graph databases). with a simple script you can obtain the followers of a user: https://gist.github.com/atomotic/f540f6d0a5d3ddf4cb25da85a330589f

the trick is to identify the admin user of an instance, that "usually" is autofollowed by new users. if you get the followers of the admin you have all users of the instance